In many occupations and recreational endeavors, a need exists for persons to be able to measure distances covered by walking or running from one point to another. For example, golfers and hikers often desire to know how far they have walked from a certain starting point or landmark and how much distance remains to an ultimate destination or intermediate point. In addition, real estate salesmen, particularly those who are engaged in commercial and industrial real estate and farm and ranch sales, often need to know with a relatively high degree of accuracy the distance across a warehouse, for example, or the length of a field and the like.
Various types of pedometers or other distance-measuring instruments have been available for indicating distances covered or distances from one point to another. Generally, pedometers which are carried on the person involve a mechanical pawl and ratchet arrangement operated under control of a weighted spring mechanism to provide a predetermined rotation or count with each step made by the person wearing the pedometer. An adjustment of the pedometer initially is made for the individual using it to cause the output reading to be indicative of the distance covered by the strides of that individual. The accuracy of such mechanical pedometers, however, is relatively poor and generally must be related to miles or tenths of a mile rather than to yards or feet over a relatively long distance. This accuracy is inadequate for golfers who are interested in accuracy within a yard or two over distances of 200 to 500 yards. Similarly, for a real estate salesman desiring to quickly obtain the dimensions of a room or a building, a much higher degree of accuracy is required than is presently obtainable from commercially available pedometers.
In addition, it is desirable to provide a pedometer which is capable of adding, with a high degree of accuracy, the distance covered by each step to give a continuous indication of the total distance covered or, alternatively, capable of subtracting from a preset distance the distance covered by each step; so that the user has an indication of the distance remaining to be traveled.
It also is desirable to obtain an accuracy with a pedometer within one or two feet over distances as much as several hundred yards and, further, it is desirable to have a capability of resetting a pedometer easily in a short period of time to adjust its operation to accommodate the strides of different persons.